Overclocking And SLI Benchmarks
These next charts demonstrate the effectiveness of factory overclocking on Asus' GTX 560 DirectCU II TOP and Zotac's GeForce GTX 560 AMP! Edition. Two reference-clocked GeForce GTX 560s in SLI are also included.
In addition, we overclocked one of our GeForce GTX 560s past the factory setting to the highest overclock we could achieve stably. While doing this we made an interesting discovery. Mainly, the Asus GTX 560 DirectCU II TOP is able to increase GPU voltage through the SmartDoctor utility. This card's stock setting is 1.012 V, but this can be increased to 1.112 V using Asus' software.
While we criticized Zotac's GeForce GTX 560 AMP! Edition for its lack of GPU voltage control, we were surprised to see GPU-Z report a stock voltage of 1.142 V. This is higher than the Asus card allows through SmartDoctor. Because of this, we expect comparatively higher GPU temperatures and power usage.
In any case, 1000 MHz was the highest frequency we were able to squeeze out of GF114 at this voltage. With a slight memory overclock to 1125 MHz, we proceed with the benchmarks:
Both of the factory overclocked cards match stock GeForce GTX 560 Ti performance. Then again, with a $220 MSRP, they also end up priced pretty close to some of the least-expensive Ti boards (selling for about $235 at the time of writing).
Note that the highest overclock we achieved manually barely made any difference compared to the factory-overclocked models. From what we’ve seen, the GF114 GPU doesn’t make it past 1 GHz easily. So, the 925+ MHz factory overclocks come so close to the card’s perceived ceiling. We probably wouldn't bother overclocking a GeForce GTX 560 unless we bought it at Nvidia's reference clocks (which do seem to leave room for higher clocks).
